Added python binding

Implemented classes:
 - elliptcis_proxy_t::remote
 - elliptcis_proxy_t::config

Example:
>>> from elliptics_proxy import *
>>> r = remote('localhost', 1025)
>>> c = config()
>>> c.remotes.append(r)
>>> c.groups.append(1)
>>> print c
remotes = [localhost:1025:2] groups = [1]
Added most functions of elliptics-proxy to binding

Implemented classes:
 - dned_id
 - key_t
 - lookup_result_t
 - data_container_t
 - async_read_result_t
 - async_write_result_t
 - async_remove_result_t
 - elliptics_proxy_t

Implemented functions of elliptics_proxy_t:
 - lookup
 - read
 - write
 - remove
 - range_get
 - bulk_read
 - lookup_addr
 - bulk_write
 - exec_script
 - read_async

and most of them was tested
Added the rest of methods of elliptics-proxy to python binding

Implemented class:
 - status_result_t

Implemented functions of elliptics_proxy_t:
 - write_async
 - remove_async
 - ping
 - stat_log
 - get_symmetric_groups
 - get_bad_groups
 - get_all_groups
Improved interface of python binding

You can use string instead of key_t to set a key
You can use string instead of data_container_t to set a dc
key_t and data_container_t can be used as before
Added enum SUCCESS_COPIES_TYPE to python binding

Using:
sa = success_copies_type.any
Fixed code to work with lazy lookup_result_t

Added wrapper python_async_write_result_t to convert std::vector of lookup_result_t to python list

Example:
	awr1 = proxy.write_async(key1, data1)
    lr = awr1.get()
	print lr

Some *_str and *_repr functions were moved to be together for clear reading of code
Added a check to avoid the use of an empty result-object into python_async_write_result_t::get and python_async_write_result_t::get_one
Added stubs for methods to work with indexes
status_result_t::la and dnet_id::id is available  to use in python

Implemented class python_dnet_id, which provides id as a python bytearray
python_key_t class is inherited from key_t and can be constructed by python_dnet_id
Implemented the set of array_to_boost_tuple functions with boost.preprocessor
Provides status_result_t::la as a tuple with array_to_boost_tuple functions
All properties in the status_result_t is now readonly
Prototypes of key_(str|repr) functions were changed to be related with new python_key_t
no_init was added to the python async result types

Is no longer possible to create objects of these types from a python script
Default constructors and checks for default-initializations were also removed
re-organized documentation

Added clear description about config
Added description to initialization example
Add description for data_container_t
Added brief description for lookup_result_t
Fixed example for synchronous write/lookup
Added methods to sync and async work with indexes of elliptics
Added description for several fields of config
Fixed (moved) description of config die_limit
Fixed example 'synchronous write/lookup'
Added asynchronous write/read example
Fixed updated_indexes

Build-fix: update_indexes_async now returns value
If you did not set data for indexes update_indexes will set it to empty